Maintenance instruction
WB
5
Before assembling make sure you have:
For WB equipped with sealing profile and separate pins
•Sealing profile (13) which consists of a rubber profile, one long
pin (13a) and two short pins (13b). Put the long pin into the sealing
and make sure it is centred. The short wires prevent the sealing
profile from being pushed into the valve body by the gate (6).
•Glue of Loctite 480 type. This is a quick-cure type of glue, means
that you have short time before it cure.
•Box packing (9), i.e. three pieces of braids.
For WB 11, WB14 and WB 12 equipped with one piece moulded sealing profile (U-shaped)
•One piece moulded sealing profile (U-shaped) (13).
•Box packing (9), i.e. 6 pieces of braids. If it is supplied with a box bottom scraper, have that also avail-
able.
Additional equipment for both types
•Synthetic lubricator (Multipurpose Grease OKS 1110 or similar grease approved for EPDM and Nitril)
•A plastic surfaced hammer and/or a pneumatic cylinder to push down the gate in closed position.
•Necessary lifting equipment for valves > DN 300.
Before assembling starts, check the gate (6) for damages such as dents and scrapes. If the gate is dam-
aged it can wear out the box packing (9), the sealing profile (13) and leakage can occur because of this.
To ensure optimal operation, Stafsjö recommends changing the gate if it is damaged.
Follow steps below to change box packing, sealing profile and gate:
1. Make sure that the valve body’s gate groove is cleaned and free from grease and residues.
2. Put the valve in a vertically up-right position in a screw vice. If the valve is supplied with a sealing pro-
file and separate pins, then use the gate as a forming tool for the sealing profile.
3. Put grease on the short end of the gate (6)
3a.For WB equipped with sealing profile and separate pins only:
Take the complete sealing profile (13) and add glue in a zigzag way on the “backside” (opposite side to
the bump). After glued the sealing you have approximately 40 seconds until the glue starts to
cure. The time for curing speeds up when the seal is mounted in the valve body. Be quick.
4. Take the sealing profile and put it into the valve’s gate groove from
the top of the valve. Make sure it is even above the stuffing box
bottom on both sides in the valve.
4a.For WB equipped with sealing profile and separate pins only:
The bump of the sealing profile must be centered and it shall face
the gate (6).
5. Push down the gate (6) to the bottom (100% closed position) of
the valve body (10)by using your own weight or use a plastic sur-
faced hammer. From DN 300 you might have to be two persons to
do this or use a pneumatic cylinder to push down the gate. Check
that the gate (6) is centered in the valve body (10) according to the
sealing profile (13), see picture to the right.
6. Let the gate stay in closed position for approximately 4 min.
7. Add box packing braids.
7a. For WB equipped with sealing profile and separate pins:
If the valve shall be equipped with a box bottom scraper, add this
first in the box bottom and then add three layers of box packing braids on top of this (9).
Make sure that each layers’ braid ends is placed on the opposite long side of the previous layer. Use a
blunt tool in plastic or wood and a hammer to push the braid into the box.
7b. For WB 11, WB14 and WB 12 equipped with one piece molded sealing profile (U-shaped):
